The use of endoscopic instruments and the adaption of video camera technology to endoscopic imaging has proven to be quite advantageous in a wide variety of surgical procedures and general diagnostic applications. Typically, an endoscopic instrument includes an elongated probe for use in penetrating and viewing remote and otherwise inaccessible body regions. Various endoscopic devices and surgical techniques have enabled the simplification of many surgical operations, and examples of commonly used endoscopic instruments include the laparascope, cystoscope, arthroscope, bronchoscope, and the colonoscope, whose names are obviously indicative of their functions and anatomical areas of use.
Conventional endoscopic systems include an endoscope, an optical adapter and a video camera head. Before each use, the endoscopic system must be adequately cleaned and sterilized, such as by soaking or immersion in a sterilizing or disinfecting solution and/or sterilization by use of ethylene oxide gas. Conventional endoscopic devices required the surgeon to view the target area directly through the eyepiece of the endoscope, which typically necessitated the surgeon bending over or otherwise situating himself in awkward positions so as to be able to view through the eyepiece. Video camera technology has been adapted to overcome these kind of inconveniences, and a typical assembly for adapting such camera technology to an endoscope includes a mechanism for grasping the endoscopic eyepiece and coupling the same to the camera head or similar equipment. The coupling device generally has a fitting at its proximal end which attaches to the video camera or an adapter unit attached to the camera head. The distal end of the coupler comprises the mechanism for grasping the endoscopic eyepiece. Often the adapter unit includes adjustable viewing optics for the video camera to provide for focusing, zoom characteristics and the like.
In addition to the need for disassembling the endoscope from the camera head and/or adapter for cleaning procedures between uses, many surgical and diagnostic procedures require the interchangeability of endoscopes during the procedure. To facilitate such interchangeability, it is preferred that the coupling mechanism be of a "quick-release" variety which is simple in operation and reliable. Because time is generally of the essence during these procedures, and with the procedures generally being of a delicate nature, the coupling mechanism must be of a relatively simple design which is easy for doctors and surgical assistants to use.
A variety of mechanisms have been implemented in the industry for releasably attaching an endoscope to a video camera head. For example, U.S. Pat. No. 4,807,594, which issued to D. Chatenever on Feb. 8, 1989 teaches the substitution of the typical eyepiece of an endoscope with a collar rotatably secured by threaded connections to a focusing adapter which is, in turn, connected to the camera head. Such arrangement thereby eliminated the eyecup of a scope and provided direct attachment of the endoscope to the camera body while allowing relative rotation therebetween. Use of this system, however, limits the interchangeability of the endoscope to particular parts designed for that adapter.
An alternative attachment arrangement shown in U.S. Pat. No. 4,369,767, which issued to Y. Shishido on Jan. 25, 1983, illustrates a radial set screw type arrangement. However, these rotatable and set screw type coupling arrangements fail to provide the relatively quick attachment/release most preferably desired in these endoscopic devices. Additionally, users of endoscopic instruments often require that the endoscope be rotatable independently of the camera head. The threaded and set screw type arrangements do not generally provide for such independent rotation.
Bayonet-type arrangements have also been widely utilized in the endoscopic device industry, as generally shown in U.S. Pat. No. 4,323,304, which issued to F. Ishii on Apr. 6, 1982. The Ishii ocular section of the endoscope is attached to a photographic camera via a plurality of bayonet pawls which radially project from the inner periphery of the connection opening. The general problem with bayonet-type locking arrangements is that they do not permit independent rotation of the endoscope relative to the camera adapter unit. U.S. Pat. No. 4,611,888, which issued to M. Prenovitz et al. on Sep. 16, 1986, discloses an improved bayonet-type, quick-release coupling arrangement which can be detached by merely a slight twist, and which includes front and rear sections which are rotatable relative one to another in order to provide rotation of the endoscope relative to the camera head, as desired. This arrangement, however, requires the replacement of the endoscopic eyepiece with a threaded collar/adapter ring arrangement. While a quick-release, rotatable assembly is provided, the modification of the endoscope eyepiece required is not always feasible and/or convenient.
U.S. Pat. No. 4,781,448, which issued to D. Chatenever et al. on Nov. 1, 1988, describes a zoom lens adapter for an endoscopic camera which includes a gripping mechanism comprising a plurality of projecting tines for removably engaging the eyecup of an endoscope. While additional details of the projecting tines of this reference are not provided, FIG. 2 of the patent illustrates a cup-shaped grasping mechanism having a circular central aperture within which the eyepiece of the endoscope is apparently inserted for grasping by the radial tines. Because of the inherent need to thoroughly clean and disinfect these devices between uses, the substantially enclosed cup-like characteristics of this grasping mechanism and its radially moveable tines cause increased difficulty in accomplishing cleaning and maintenance of the device, and can allow moisture to collect and interfere with optimal use of these devices. For example, such moisture can condense and fog the optics in use. Furthermore, such structure does not provide a relatively clear view of the coupling mechanism in use to assure that the scope is firmly locked in place and to avoid accidental disconnection and damage which can result therefrom.
Similar mounting devices or endoscopic eyepieces are shown in U.S. Pat. Nos. 4,305,386 and 4,318,395 which issued to I. Tawara. These references discuss the shortcomings of the bayonet-type and friction-type mounting devices commonly available in the industry, specifying that such devices lack the ability to provide immovable and rotatable connection of the ocular device. The Tawara mounting devices utilize one or more swingable or rockable cams which are normally biased inwardly by tension springs, whereby an ocular device may be snapped into the inner portions of an inwardly tapered conical cavity. Immovable clamping can be obtained by rotation of a fixing cam ring, and release of the eyepiece can be obtained by appropriate rotation of a release cam ring. These systems are relatively complicated in their use of a plurality of cams, springs, and rotatable rings. Additionally, the requirement of an inwardly tapered conical cavity makes cleaning and maintenance more difficult, and substantially obstructs the view of the user during actual use of the device.
An expanding-type coupling apparatus is shown in U.S. Pat. No. 4,413,278, which issued to R. Feinbloom on Nov. 1, 1983. The Feinbloom device includes two semi-circular arms which are pivotally attached at their lower ends and biased by a pair of springs at their upper ends. These opposed C-shaped arms are mounted within an aperture formed in a front cover, and can be moved radially to enable the placement or removal of the front section of an arthroscope therewithin. Again, this arrangement does not provide for convenient cleaning and/or maintenance, and does not provide for substantially unencumbered viewing of the coupling mechanism in use.
Most recently, there are a variety of coupling mechanisms available in the industry from companies such as Stryker and Zimmer which comprise an elongated, unitary ring-like element located between an outer cover member and an inner alignment surface for an endoscopic eyepiece. The ring-like device includes a tapered clamping surface which is spaced from the alignment surface to accommodate the thickness of the eyepiece, and is normally urged into an engagement position with an eyepiece located within the coupler. The ring-like member can be axially reciprocated to move the clamping portion out of engagement with the eyepiece for release. Again, however, these ring-like coupling mechanisms are quite similar to the Feinbloom mechanism in that they do not substantially address the problems of facilitating ease of cleaning and maintenance, and do not provide a compact coupling mechanism of substantially open character which permits relatively unencumbered viewing of the coupling mechanism in use to facilitate attachment and release procedures and enhances air circulation to obviate collection of moisture. Additionally, the spacing of the ring-like member from the alignment surface adds size and bulk to the assembly.
As a result, heretofore, there has not been available in the industry a relatively simple and compact, easy-to-use endoscopic coupling mechanism which is substantially open at its distal end for simplified manufacture, use, maintenance and cleanup. While various quick-release mechanisms have become available in the industry, none permit substantially unrestricted access to the eyepiece mounting surface in use, while providing a simplified operating mechanism which will not only facilitate the attachment and replacement of various endoscopic eyepieces by a surgeon or technician, but will further simplify and prove the efficiency of cleaning procedures, sterilization, maintenance, antifogging, and verification of secure attachment.